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1da177e4 LT |
1 | /* |
2 | * linux/include/asm-arm/uaccess.h | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | #ifndef _ASMARM_UACCESS_H | |
9 | #define _ASMARM_UACCESS_H | |
10 | ||
11 | /* | |
12 | * User space memory access functions | |
13 | */ | |
14 | #include <linux/sched.h> | |
15 | #include <asm/errno.h> | |
16 | #include <asm/memory.h> | |
17 | #include <asm/domain.h> | |
18 | #include <asm/system.h> | |
19 | ||
20 | #define VERIFY_READ 0 | |
21 | #define VERIFY_WRITE 1 | |
22 | ||
23 | /* | |
24 | * The exception table consists of pairs of addresses: the first is the | |
25 | * address of an instruction that is allowed to fault, and the second is | |
26 | * the address at which the program should continue. No registers are | |
27 | * modified, so it is entirely up to the continuation code to figure out | |
28 | * what to do. | |
29 | * | |
30 | * All the routines below use bits of fixup code that are out of line | |
31 | * with the main instruction path. This means when everything is well, | |
32 | * we don't even have to jump over them. Further, they do not intrude | |
33 | * on our cache or tlb entries. | |
34 | */ | |
35 | ||
36 | struct exception_table_entry | |
37 | { | |
38 | unsigned long insn, fixup; | |
39 | }; | |
40 | ||
41 | extern int fixup_exception(struct pt_regs *regs); | |
42 | ||
43 | /* | |
44 | * Note that this is actually 0x1,0000,0000 | |
45 | */ | |
46 | #define KERNEL_DS 0x00000000 | |
47 | #define USER_DS TASK_SIZE | |
48 | ||
49 | #define get_ds() (KERNEL_DS) | |
50 | #define get_fs() (current_thread_info()->addr_limit) | |
51 | ||
52 | static inline void set_fs (mm_segment_t fs) | |
53 | { | |
54 | current_thread_info()->addr_limit = fs; | |
55 | modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER); | |
56 | } | |
57 | ||
58 | #define segment_eq(a,b) ((a) == (b)) | |
59 | ||
60 | #define __addr_ok(addr) ({ \ | |
61 | unsigned long flag; \ | |
62 | __asm__("cmp %2, %0; movlo %0, #0" \ | |
63 | : "=&r" (flag) \ | |
64 | : "0" (current_thread_info()->addr_limit), "r" (addr) \ | |
65 | : "cc"); \ | |
66 | (flag == 0); }) | |
67 | ||
68 | /* We use 33-bit arithmetic here... */ | |
69 | #define __range_ok(addr,size) ({ \ | |
70 | unsigned long flag, sum; \ | |
71 | __chk_user_ptr(addr); \ | |
72 | __asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \ | |
73 | : "=&r" (flag), "=&r" (sum) \ | |
74 | : "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \ | |
75 | : "cc"); \ | |
76 | flag; }) | |
77 | ||
78 | #define access_ok(type,addr,size) (__range_ok(addr,size) == 0) | |
79 | ||
1da177e4 LT |
80 | /* |
81 | * Single-value transfer routines. They automatically use the right | |
82 | * size if we just have the right pointer type. Note that the functions | |
83 | * which read from user space (*get_*) need to take care not to leak | |
84 | * kernel data even if the calling code is buggy and fails to check | |
85 | * the return value. This means zeroing out the destination variable | |
86 | * or buffer on error. Normally this is done out of line by the | |
87 | * fixup code, but there are a few places where it intrudes on the | |
88 | * main code path. When we only write to user space, there is no | |
89 | * problem. | |
90 | * | |
91 | * The "__xxx" versions of the user access functions do not verify the | |
92 | * address space - it must have been done previously with a separate | |
93 | * "access_ok()" call. | |
94 | * | |
95 | * The "xxx_error" versions set the third argument to EFAULT if an | |
96 | * error occurs, and leave it unchanged on success. Note that these | |
97 | * versions are void (ie, don't return a value as such). | |
98 | */ | |
99 | ||
100 | extern int __get_user_1(void *); | |
101 | extern int __get_user_2(void *); | |
102 | extern int __get_user_4(void *); | |
103 | extern int __get_user_8(void *); | |
104 | extern int __get_user_bad(void); | |
105 | ||
106 | #define __get_user_x(__r2,__p,__e,__s,__i...) \ | |
107 | __asm__ __volatile__ ( \ | |
108 | __asmeq("%0", "r0") __asmeq("%1", "r2") \ | |
109 | "bl __get_user_" #__s \ | |
110 | : "=&r" (__e), "=r" (__r2) \ | |
111 | : "0" (__p) \ | |
112 | : __i, "cc") | |
113 | ||
114 | #define get_user(x,p) \ | |
115 | ({ \ | |
116 | const register typeof(*(p)) __user *__p asm("r0") = (p);\ | |
117 | register typeof(*(p)) __r2 asm("r2"); \ | |
118 | register int __e asm("r0"); \ | |
119 | switch (sizeof(*(__p))) { \ | |
120 | case 1: \ | |
121 | __get_user_x(__r2, __p, __e, 1, "lr"); \ | |
122 | break; \ | |
123 | case 2: \ | |
124 | __get_user_x(__r2, __p, __e, 2, "r3", "lr"); \ | |
125 | break; \ | |
126 | case 4: \ | |
127 | __get_user_x(__r2, __p, __e, 4, "lr"); \ | |
128 | break; \ | |
129 | case 8: \ | |
130 | __get_user_x(__r2, __p, __e, 8, "lr"); \ | |
131 | break; \ | |
132 | default: __e = __get_user_bad(); break; \ | |
133 | } \ | |
134 | x = __r2; \ | |
135 | __e; \ | |
136 | }) | |
137 | ||
138 | #define __get_user(x,ptr) \ | |
139 | ({ \ | |
140 | long __gu_err = 0; \ | |
141 | __get_user_err((x),(ptr),__gu_err); \ | |
142 | __gu_err; \ | |
143 | }) | |
144 | ||
145 | #define __get_user_error(x,ptr,err) \ | |
146 | ({ \ | |
147 | __get_user_err((x),(ptr),err); \ | |
148 | (void) 0; \ | |
149 | }) | |
150 | ||
151 | #define __get_user_err(x,ptr,err) \ | |
152 | do { \ | |
153 | unsigned long __gu_addr = (unsigned long)(ptr); \ | |
154 | unsigned long __gu_val; \ | |
155 | __chk_user_ptr(ptr); \ | |
156 | switch (sizeof(*(ptr))) { \ | |
157 | case 1: __get_user_asm_byte(__gu_val,__gu_addr,err); break; \ | |
158 | case 2: __get_user_asm_half(__gu_val,__gu_addr,err); break; \ | |
159 | case 4: __get_user_asm_word(__gu_val,__gu_addr,err); break; \ | |
160 | default: (__gu_val) = __get_user_bad(); \ | |
161 | } \ | |
162 | (x) = (__typeof__(*(ptr)))__gu_val; \ | |
163 | } while (0) | |
164 | ||
165 | #define __get_user_asm_byte(x,addr,err) \ | |
166 | __asm__ __volatile__( \ | |
167 | "1: ldrbt %1,[%2],#0\n" \ | |
168 | "2:\n" \ | |
169 | " .section .fixup,\"ax\"\n" \ | |
170 | " .align 2\n" \ | |
171 | "3: mov %0, %3\n" \ | |
172 | " mov %1, #0\n" \ | |
173 | " b 2b\n" \ | |
174 | " .previous\n" \ | |
175 | " .section __ex_table,\"a\"\n" \ | |
176 | " .align 3\n" \ | |
177 | " .long 1b, 3b\n" \ | |
178 | " .previous" \ | |
179 | : "+r" (err), "=&r" (x) \ | |
180 | : "r" (addr), "i" (-EFAULT) \ | |
181 | : "cc") | |
182 | ||
183 | #ifndef __ARMEB__ | |
184 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
185 | ({ \ | |
186 | unsigned long __b1, __b2; \ | |
187 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
188 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
189 | (x) = __b1 | (__b2 << 8); \ | |
190 | }) | |
191 | #else | |
192 | #define __get_user_asm_half(x,__gu_addr,err) \ | |
193 | ({ \ | |
194 | unsigned long __b1, __b2; \ | |
195 | __get_user_asm_byte(__b1, __gu_addr, err); \ | |
196 | __get_user_asm_byte(__b2, __gu_addr + 1, err); \ | |
197 | (x) = (__b1 << 8) | __b2; \ | |
198 | }) | |
199 | #endif | |
200 | ||
201 | #define __get_user_asm_word(x,addr,err) \ | |
202 | __asm__ __volatile__( \ | |
203 | "1: ldrt %1,[%2],#0\n" \ | |
204 | "2:\n" \ | |
205 | " .section .fixup,\"ax\"\n" \ | |
206 | " .align 2\n" \ | |
207 | "3: mov %0, %3\n" \ | |
208 | " mov %1, #0\n" \ | |
209 | " b 2b\n" \ | |
210 | " .previous\n" \ | |
211 | " .section __ex_table,\"a\"\n" \ | |
212 | " .align 3\n" \ | |
213 | " .long 1b, 3b\n" \ | |
214 | " .previous" \ | |
215 | : "+r" (err), "=&r" (x) \ | |
216 | : "r" (addr), "i" (-EFAULT) \ | |
217 | : "cc") | |
218 | ||
219 | extern int __put_user_1(void *, unsigned int); | |
220 | extern int __put_user_2(void *, unsigned int); | |
221 | extern int __put_user_4(void *, unsigned int); | |
222 | extern int __put_user_8(void *, unsigned long long); | |
223 | extern int __put_user_bad(void); | |
224 | ||
225 | #define __put_user_x(__r2,__p,__e,__s) \ | |
226 | __asm__ __volatile__ ( \ | |
227 | __asmeq("%0", "r0") __asmeq("%2", "r2") \ | |
228 | "bl __put_user_" #__s \ | |
229 | : "=&r" (__e) \ | |
230 | : "0" (__p), "r" (__r2) \ | |
231 | : "ip", "lr", "cc") | |
232 | ||
233 | #define put_user(x,p) \ | |
234 | ({ \ | |
235 | const register typeof(*(p)) __r2 asm("r2") = (x); \ | |
236 | const register typeof(*(p)) __user *__p asm("r0") = (p);\ | |
237 | register int __e asm("r0"); \ | |
238 | switch (sizeof(*(__p))) { \ | |
239 | case 1: \ | |
240 | __put_user_x(__r2, __p, __e, 1); \ | |
241 | break; \ | |
242 | case 2: \ | |
243 | __put_user_x(__r2, __p, __e, 2); \ | |
244 | break; \ | |
245 | case 4: \ | |
246 | __put_user_x(__r2, __p, __e, 4); \ | |
247 | break; \ | |
248 | case 8: \ | |
249 | __put_user_x(__r2, __p, __e, 8); \ | |
250 | break; \ | |
251 | default: __e = __put_user_bad(); break; \ | |
252 | } \ | |
253 | __e; \ | |
254 | }) | |
255 | ||
256 | #define __put_user(x,ptr) \ | |
257 | ({ \ | |
258 | long __pu_err = 0; \ | |
259 | __put_user_err((x),(ptr),__pu_err); \ | |
260 | __pu_err; \ | |
261 | }) | |
262 | ||
263 | #define __put_user_error(x,ptr,err) \ | |
264 | ({ \ | |
265 | __put_user_err((x),(ptr),err); \ | |
266 | (void) 0; \ | |
267 | }) | |
268 | ||
269 | #define __put_user_err(x,ptr,err) \ | |
270 | do { \ | |
271 | unsigned long __pu_addr = (unsigned long)(ptr); \ | |
272 | __typeof__(*(ptr)) __pu_val = (x); \ | |
273 | __chk_user_ptr(ptr); \ | |
274 | switch (sizeof(*(ptr))) { \ | |
275 | case 1: __put_user_asm_byte(__pu_val,__pu_addr,err); break; \ | |
276 | case 2: __put_user_asm_half(__pu_val,__pu_addr,err); break; \ | |
277 | case 4: __put_user_asm_word(__pu_val,__pu_addr,err); break; \ | |
278 | case 8: __put_user_asm_dword(__pu_val,__pu_addr,err); break; \ | |
279 | default: __put_user_bad(); \ | |
280 | } \ | |
281 | } while (0) | |
282 | ||
283 | #define __put_user_asm_byte(x,__pu_addr,err) \ | |
284 | __asm__ __volatile__( \ | |
285 | "1: strbt %1,[%2],#0\n" \ | |
286 | "2:\n" \ | |
287 | " .section .fixup,\"ax\"\n" \ | |
288 | " .align 2\n" \ | |
289 | "3: mov %0, %3\n" \ | |
290 | " b 2b\n" \ | |
291 | " .previous\n" \ | |
292 | " .section __ex_table,\"a\"\n" \ | |
293 | " .align 3\n" \ | |
294 | " .long 1b, 3b\n" \ | |
295 | " .previous" \ | |
296 | : "+r" (err) \ | |
297 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
298 | : "cc") | |
299 | ||
300 | #ifndef __ARMEB__ | |
301 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
302 | ({ \ | |
303 | unsigned long __temp = (unsigned long)(x); \ | |
304 | __put_user_asm_byte(__temp, __pu_addr, err); \ | |
305 | __put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \ | |
306 | }) | |
307 | #else | |
308 | #define __put_user_asm_half(x,__pu_addr,err) \ | |
309 | ({ \ | |
310 | unsigned long __temp = (unsigned long)(x); \ | |
311 | __put_user_asm_byte(__temp >> 8, __pu_addr, err); \ | |
312 | __put_user_asm_byte(__temp, __pu_addr + 1, err); \ | |
313 | }) | |
314 | #endif | |
315 | ||
316 | #define __put_user_asm_word(x,__pu_addr,err) \ | |
317 | __asm__ __volatile__( \ | |
318 | "1: strt %1,[%2],#0\n" \ | |
319 | "2:\n" \ | |
320 | " .section .fixup,\"ax\"\n" \ | |
321 | " .align 2\n" \ | |
322 | "3: mov %0, %3\n" \ | |
323 | " b 2b\n" \ | |
324 | " .previous\n" \ | |
325 | " .section __ex_table,\"a\"\n" \ | |
326 | " .align 3\n" \ | |
327 | " .long 1b, 3b\n" \ | |
328 | " .previous" \ | |
329 | : "+r" (err) \ | |
330 | : "r" (x), "r" (__pu_addr), "i" (-EFAULT) \ | |
331 | : "cc") | |
332 | ||
333 | #ifndef __ARMEB__ | |
334 | #define __reg_oper0 "%R2" | |
335 | #define __reg_oper1 "%Q2" | |
336 | #else | |
337 | #define __reg_oper0 "%Q2" | |
338 | #define __reg_oper1 "%R2" | |
339 | #endif | |
340 | ||
341 | #define __put_user_asm_dword(x,__pu_addr,err) \ | |
342 | __asm__ __volatile__( \ | |
343 | "1: strt " __reg_oper1 ", [%1], #4\n" \ | |
344 | "2: strt " __reg_oper0 ", [%1], #0\n" \ | |
345 | "3:\n" \ | |
346 | " .section .fixup,\"ax\"\n" \ | |
347 | " .align 2\n" \ | |
348 | "4: mov %0, %3\n" \ | |
349 | " b 3b\n" \ | |
350 | " .previous\n" \ | |
351 | " .section __ex_table,\"a\"\n" \ | |
352 | " .align 3\n" \ | |
353 | " .long 1b, 4b\n" \ | |
354 | " .long 2b, 4b\n" \ | |
355 | " .previous" \ | |
356 | : "+r" (err), "+r" (__pu_addr) \ | |
357 | : "r" (x), "i" (-EFAULT) \ | |
358 | : "cc") | |
359 | ||
360 | extern unsigned long __arch_copy_from_user(void *to, const void __user *from, unsigned long n); | |
361 | extern unsigned long __arch_copy_to_user(void __user *to, const void *from, unsigned long n); | |
362 | extern unsigned long __arch_clear_user(void __user *addr, unsigned long n); | |
363 | extern unsigned long __arch_strncpy_from_user(char *to, const char __user *from, unsigned long count); | |
364 | extern unsigned long __arch_strnlen_user(const char __user *s, long n); | |
365 | ||
366 | static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) | |
367 | { | |
368 | if (access_ok(VERIFY_READ, from, n)) | |
369 | n = __arch_copy_from_user(to, from, n); | |
370 | else /* security hole - plug it */ | |
371 | memzero(to, n); | |
372 | return n; | |
373 | } | |
374 | ||
375 | static inline unsigned long __copy_from_user(void *to, const void __user *from, unsigned long n) | |
376 | { | |
377 | return __arch_copy_from_user(to, from, n); | |
378 | } | |
379 | ||
380 | static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) | |
381 | { | |
382 | if (access_ok(VERIFY_WRITE, to, n)) | |
383 | n = __arch_copy_to_user(to, from, n); | |
384 | return n; | |
385 | } | |
386 | ||
387 | static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n) | |
388 | { | |
389 | return __arch_copy_to_user(to, from, n); | |
390 | } | |
391 | ||
392 | #define __copy_to_user_inatomic __copy_to_user | |
393 | #define __copy_from_user_inatomic __copy_from_user | |
394 | ||
395 | static inline unsigned long clear_user (void __user *to, unsigned long n) | |
396 | { | |
397 | if (access_ok(VERIFY_WRITE, to, n)) | |
398 | n = __arch_clear_user(to, n); | |
399 | return n; | |
400 | } | |
401 | ||
402 | static inline unsigned long __clear_user (void __user *to, unsigned long n) | |
403 | { | |
404 | return __arch_clear_user(to, n); | |
405 | } | |
406 | ||
407 | static inline long strncpy_from_user (char *dst, const char __user *src, long count) | |
408 | { | |
409 | long res = -EFAULT; | |
410 | if (access_ok(VERIFY_READ, src, 1)) | |
411 | res = __arch_strncpy_from_user(dst, src, count); | |
412 | return res; | |
413 | } | |
414 | ||
415 | static inline long __strncpy_from_user (char *dst, const char __user *src, long count) | |
416 | { | |
417 | return __arch_strncpy_from_user(dst, src, count); | |
418 | } | |
419 | ||
420 | #define strlen_user(s) strnlen_user(s, ~0UL >> 1) | |
421 | ||
422 | static inline long strnlen_user(const char __user *s, long n) | |
423 | { | |
424 | unsigned long res = 0; | |
425 | ||
426 | if (__addr_ok(s)) | |
427 | res = __arch_strnlen_user(s, n); | |
428 | ||
429 | return res; | |
430 | } | |
431 | ||
432 | #endif /* _ASMARM_UACCESS_H */ |